Treatment of Aseptic Necrosis of the Lunate Bone (Kienböck Disease) Using a Nickel–Titanium Memory Alloy Arthrodesis Concentrator: A Series of 24 Cases

Avascular necrosis of the lunate bone (Kienböck disease) is caused by loss of blood supply of the bone. This study aimed to evaluate the efficacy and safety of a novel nickel–titanium (Ni–Ti) memory alloy arthrodesis concentrator in the treatment of this disease. A consecutive 24 patients with stage IIIb aseptic lunate necrosis were treated with scapho-trapezio-trapezoeid (STT) arthrodesis using a Ni–Ti arthrodesis concentrator from August 2008 to December 2012. Wrist pain, grip strength, carpal height, and scapholunate angle were measured and compared before and after the surgery. The wrist functions were evaluated using the Mayo scale. Patients were followed up for a mean of 12 months (range, 6–24 months). Grip strength of the affected side was significantly improved after the surgery (18 ± 4.74 kg vs. 30.21 ± 7.14 kg, P < 0.0001). Wrist pain score was significantly decreased from 5.88 ± 0.9 to 0.5 ± 0.51 (P < 0.0001). Carpal height and Mayo score were also significantly increased after the surgery (P < 0.0001). Scapholunate angle was significantly decreased after the surgery (68.38 ± 7.28° vs. 49.91 ± 4.28°, P < 0.0001). No implant breakage, loose implant, wound infection, or nonunion occurred. STT arthrodesis is effective for the treatment of stage IIIb lunate necrosis. The Ni–Ti memory alloy arthrodesis concentrator is a convenient tool for STT arthrodesis with excellent and reliable results.